import re
import sqlite3 as db
import sys
import uuid

import db_setup
from game import money_amount
from util import debug

connection = None
cursor = None
db_name = None


def query_save_name():
    global db_name
    if debug:
        db_name = 'test.db'
        return
    while True:
        save_name = input('Name of the savegame: ')
        if re.match(r"[A-Za-z0-9.-]{0,50}", save_name):
            db_name = save_name + '.db'
            return


def connect(reconnect=False):
    global connection
    global cursor
    global db_name
    if reconnect:
        connection.commit()
        connection.close()
        cursor = None
        connection = None
        db_name = None

    if connection is None or cursor is None:
        query_save_name()

        try:
            connection = db.connect(db_name)

            cursor = connection.cursor()

        except db.Error as e:
            print("Database error %s:" % e.args[0])
            sys.exit(1)

        # finally:
        #     if con is not None:
        #         con.close()


def setup():
    connect()

    db_setup.setup()

    connection.commit()


def login(username, password):
    connect()

    # do not allow login as bank
    if password == '':
        return None

    cursor.execute('''
                SELECT rowid
                FROM users
                WHERE username = ?
                AND password = ?
                ''', (username, password))
    user_id = cursor.fetchone()
    if user_id:
        return new_session(user_id)
    else:
        return None


def register(username, password, game_key):
    connect()
    if username == '':
        return False
    if password == '':
        return False
    cursor.execute('''
                INSERT INTO users 
                (username, password)
                VALUES (? , ?)
                ''', (username, password))
    if game_key is not None:
        if game_key in unused_keys():
            cursor.execute('''
                        UPDATE keys
                        WHERE used_by_user_id IS NULL
                        AND key = ?
                        SET used_by_user_id = (
                            SELECT rowid
                            FROM users
                            WHERE username = ?
                        )
                        ''', (game_key, username))
        if cursor.fetchone()[0]!=1:
            raise AssertionError()
        # TODO: assign some money form bank

    return True


def new_session(user_id):
    connect()

    session_id = str(uuid.uuid4())

    cursor.execute('''
                INSERT INTO SESSIONS 
                (user_id, session_id)
                VALUES (? , ?)
                ''', (user_id[0], session_id))

    return session_id


def save_key(key):
    connect()

    cursor.execute('''
                INSERT INTO keys 
                (key)
                VALUES (?)
                ''', (key,))


def drop_old_sessions():
    connect()
    # TODO: test
    cursor.execute('''
                DELETE FROM sessions s1
                WHERE 
                    (SELECT COUNT(*) as newer
                     FROM sessions s2
                     WHERE s1.user_id = s2.user_id
                     AND s1.rowid < s2.rowid) >= 10
                ''')


def user_exists(username):
    connect()

    cursor.execute('''
                SELECT rowid
                FROM users
                WHERE username = ?
                ''', (username,))

    if cursor.fetchone():
        return True
    else:
        return False


def unused_keys():
    connect()

    cursor.execute('''
        SELECT key
        FROM keys
        WHERE used_by_user_id IS NULL
        ''')

    return [str(key[0]).strip().upper() for key in cursor.fetchall()]